The present invention relates to a heat-sensitive, color-producing composition which is especially suitable for making heat-sensitive recording members and paints, and more paticularly to a composition containing a metallic compound and chelating agent capable of being chelated with a metal in said metallic compound, in which both components are separated from each other by including either or both of them into a heat-fusible material.
Several attempts have been made to prepare heat-sensitive recording members. One of them comprises mixing two substances which chemically react with each other when heated, dispersing the mixture into a suitable binder and then coating the dispersion onto a sheet like material. Another attempt comprises dispersing two substances, separately, into suitable binders and then coating two dispersions successively onto a sheet-like material, or providing two dispersions, coating the dispersions onto two separaate sheet-like materials and then combined the two coated materials to make a recording member, whereby said two substances are separated from each other and thus discoloration due to spontaneous chemical reactions is avoided.
However, the recording members thus prepared have suffered considerable discoloration on their surface with the lapse of time and could not attain their objects. Thus, even if such heat-sensitive recording members were exposed to heat through an original to obtain an image thereon, contrast of the image was poor and this was a great impediment in the reading of the recorded article. It was also impossible to semipermanently preserve the recorded article as it is.